<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <script src="js/jquery-3.3.1.js"></script>
    <script src="js/4.js"></script>
    <title>Title</title>

</head>
<body>

<div>
  <div id="d1">11111</div>
  <div style="height:200px;background:darkblue;display:none">2</div>
</div>

</body>
</html>